<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    input{
      display: block;
      margin-bottom: 10px;
    }
  </style>
</head>
<body>
  <input type="date">
  <input type="datetime">
  <input type="datetime-local">
  <input type="text" value="" maxlength="100" id="Text4" onclick="SelectDate(this,'yyyy-MM-dd hh:mm:ss')"/>  
  <script>
    console.log(f1());
    console.log(f2);
    function f1(){
      console.log('aa');
      return undefined
    }
    var f2 = function(){}

  </script>
</body>
</html>